Online monitoring of wire breaks in prestressed concrete cylinder pipe utilising fibre Bragg grating sensors

With steel prestressing wires tensioned around core, Prestressed Concrete Cylinder Pipe (PCCP) is a high-strength composite pipe designed for large-diameter water propagation and distribution. However, some PCCPs may fail after a certain time of service due to corrosion and deterioration. Real-time health monitoring of wire breaks is essential to assess the condition and avoid catastrophic failures of PCCPs. In this paper, a novel approach based on Fibre Bragg Grating (FBG) sensing technology, is presented to monitor and locate wire breaks in PCCP lines. FBG vibration sensors are utilised to capture the signals of wire break activities in the pipeline and obtain their locations. The online monitoring system and localization principle of wire break activities are described. Preliminary experiments were carried out on PCCPs with an inner diameter of 2 m, which were filled with pressurized water. Experimental results indicate that the wire break activity can be detected and located effectively by FBG sensors. The detection error of wire break locations is analysed. With unique features, the proposed non-destructive method is expected to be used for the online monitoring of wire break activities in long term for the condition assessment and performance prediction of PCCP lines.